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ALSA: pcm: Add stream lock during PCM reset ioctl operations

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snd_pcm_reset() is a non-atomic operation, and it's allowed to run
during the PCM stream running.  It implies that the manipulation of
hw_ptr and other parameters might be racy.

This patch adds the PCM stream lock at appropriate places in
snd_pcm_*_reset() actions for covering that.

Cc: <stable@vger.kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220322171325.4355-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2022-03-22 18:13:25 +01:00
parent 69534c48ba
commit 1f68915b2e
1 changed files with 4 additions and 0 deletions
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4
sound/core/pcm_native.c
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@ -1864,11 +1864,13 @@ static int snd_pcm_do_reset(struct snd_pcm_substream *substream,
int err = snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_RESET, NULL); int err = snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_RESET, NULL);
if (err < 0) if (err < 0)
return err; return err;
snd_pcm_stream_lock_irq(substream);
runtime->hw_ptr_base = 0; runtime->hw_ptr_base = 0;
runtime->hw_ptr_interrupt = runtime->status->hw_ptr - runtime->hw_ptr_interrupt = runtime->status->hw_ptr -
runtime->status->hw_ptr % runtime->period_size; runtime->status->hw_ptr % runtime->period_size;
runtime->silence_start = runtime->status->hw_ptr; runtime->silence_start = runtime->status->hw_ptr;
runtime->silence_filled = 0; runtime->silence_filled = 0;
snd_pcm_stream_unlock_irq(substream);
return 0; return 0;
} }
@ -1876,10 +1878,12 @@ static void snd_pcm_post_reset(struct snd_pcm_substream *substream,
snd_pcm_state_t state) snd_pcm_state_t state)
{ {
struct snd_pcm_runtime *runtime = substream->runtime; struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_stream_lock_irq(substream);
runtime->control->appl_ptr = runtime->status->hw_ptr; runtime->control->appl_ptr = runtime->status->hw_ptr;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
runtime->silence_size > 0) runtime->silence_size > 0)
snd_pcm_playback_silence(substream, ULONG_MAX); snd_pcm_playback_silence(substream, ULONG_MAX);
snd_pcm_stream_unlock_irq(substream);
} }
static const struct action_ops snd_pcm_action_reset = { static const struct action_ops snd_pcm_action_reset = {